81306711760 has 40 divisors (see below), whose sum is σ = 190094217120. Its totient is φ = 32340988032.

The previous prime is 81306711749. The next prime is 81306711763. The reversal of 81306711760 is 6711760318.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×81306711760² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81306711763) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2824602 + ... + 2853241.

It is an arithmetic number, because the mean of its divisors is an integer number (4752355428).

Almost surely, 2^81306711760 is an apocalyptic number.

81306711760 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81306711760 is an abundant number, since it is smaller than the sum of its proper divisors (108787505360).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81306711760 is a wasteful number, since it uses less digits than its factorization.

81306711760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5678035 (or 5678029 counting only the distinct ones).

The product of its (nonzero) digits is 42336, while the sum is 40.

The spelling of 81306711760 in words is "eighty-one billion, three hundred six million, seven hundred eleven thousand, seven hundred sixty".